Optical lens, camera module and microscope

Abstract

The embodiment of the utility model relates to the technical field of optical imaging, and provides an optical lens, a camera module and a microscope, and the optical lens comprises twelve lenses which are arranged from an image side to an object side. In the direction from the image side to the object side, the lens located at the first position and the lens located at the second position form a first glued lens, and the focal power of the first glued lens is negative; the focal length EFL of the optical lens meets the relational expression: 3.5 < = EFL < = 6.5; the entrance pupil diameter ENTD of the optical lens satisfies the relational expression: 6.6 < = ENTD < = 9.5. The optical lens achieves the purposes of large numerical aperture, long working distance and high resolution.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical imaging technology, and in particular to an optical lens, a camera module and a microscope. BACKGROUND

[0002] Microscopes have important applications in many fields such as biology, medicine, material science, nanotechnology, etc. With the increasing requirements for observation resolution, imaging speed and working distance in the field of industrial semiconductor detection, the performance of microscope objectives is gradually improved, and the microscope objectives gradually tend to have a larger field of view, a larger numerical aperture and a better and safer working distance. To improve the clarity of the microscope, the magnification of the microscope objective can be increased, and the numerical aperture can be increased. However, a larger magnification usually means a shorter focal length, and the working distance of a large numerical aperture is usually short, which is inconvenient in many occasions. SUMMARY

[0003] Embodiments of the present application provide an optical lens and a camera module, which are used to solve the problem that the microscope objective in the related art cannot simultaneously have a large numerical aperture, a long working distance and high resolution.

[0004] To achieve the above-mentioned purpose, embodiments of the present application adopt the following technical solutions:

[0005] In a first aspect, embodiments of the present application provide an optical lens applied to a microscope, the optical lens comprising twelve lenses; from an image side to an object side, the lens located at a first position and the lens located at a second position form a first cemented lens, the optical power of the first cemented lens being negative; the focal length EFL of the optical lens satisfies the relationship: 3.5≤EFL≤6.5; the entrance pupil diameter ENTD of the optical lens satisfies the relationship: 6.6≤ENTD≤9.5.

[0006] In some embodiments, the total optical length TTL of the optical lens satisfies the relationship: TTL≤68mm.

[0007] In some embodiments, the curvature radius R 12A of the image side of the lens located at the last position arranged from the image side to the object side and the curvature radius R 12B of the object side satisfy the relationship: 0.267≤R 12A / R 12B ≤0.514.

[0008] In some embodiments, the combined focal length F 10_11_12 of the three lenses located at the last three positions arranged from the image side to the object side and the focal length EFL of the optical lens satisfy the relationship: 1.26≤F 10_11_12 / EFL≤2.1.

[0009] In some embodiments, the maximum aperture D MAX of the optical lens satisfies the relationship: 1.809 < |D MIN | / D MAX | < 2.5. MIN

[0010] In some embodiments, the optical lens comprises, in order from the image side to the object side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, and a twelfth lens; the first lens and the second lens form the first cemented lens, the third lens, the fourth lens, and the fifth lens form the second cemented lens, and the sixth lens and the seventh lens form the third cemented lens.

[0011] In some embodiments, the optical lens comprises, in order from the image side to the object side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, and a twelfth lens; the first lens is a biconvex lens with positive optical power, the second lens is a biconcave lens with negative optical power, the third lens is a biconvex lens with positive optical power, the fourth lens is a biconcave lens with negative optical power, the fifth lens is a biconvex lens with positive optical power, the sixth lens is a biconvex lens with positive optical power, the seventh lens is a meniscus lens or a biconcave lens with negative optical power, the eighth lens is a biconvex lens with positive optical power, the ninth lens is a biconcave lens with negative optical power, the tenth lens is a biconvex lens with positive optical power, the eleventh lens is a meniscus lens with positive optical power, and the twelfth lens is a meniscus lens with positive optical power.

[0012] In some embodiments, the second cemented lens has negative optical power, and the third cemented lens has positive optical power.

[0013] In some embodiments, the optical lens further comprises a diaphragm, which is located between the ninth lens and the tenth lens.

[0014] In some embodiments, the optical lens further comprises a cover glass, which is located on the side of the twelfth lens close to the object plane.

[0015] ​In the twelve lenses of the optical lens in the embodiment of the present application, from the image side to the object side, the lens at the first position and the lens at the second position form a first cemented lens, that is, the first position close to the image side is the first cemented lens, the optical power of the first cemented lens is negative, forming a reverse telephoto structure, and on this basis, on the one hand, by reasonably selecting the entrance pupil diameter of the optical lens, the numerical aperture can be appropriately reduced, so as to achieve the purpose of giving consideration to large numerical aperture and long working distance; on the other hand, the design of the first cemented lens reduces the tolerance sensitivity of the optical lens, and by reasonably selecting the optical power of each lens, when the focal length of the optical lens satisfies the above relationship, it is beneficial to reduce the aberration of the optical lens, thereby improving the resolution of the optical lens, and further making the optical lens achieve the purpose of giving consideration to large numerical aperture, long working distance and high resolution.

[0016] In a second aspect, the embodiment of the present application provides a microscope, which comprises the optical lens as described in the first aspect.

[0017] The optical lens in the microscope of the embodiment of the present application has the same structure and technical effects as the optical lens in the first aspect, and will not be described here.

[0018] In a third aspect, the embodiment of the present application provides a camera module, which comprises a photosensitive element and the optical lens as described in the first aspect, and the photosensitive element is arranged on the image side of the optical lens.

[0019] The optical lens in the camera module of the embodiment of the present application has the same structure and technical effects as the optical lens in the first aspect, and will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A structural schematic diagram of the optical lens provided for the embodiment one of the present application;

[0021] Figure 2 An MTF diagram of the optical lens provided for the embodiment one of the present application;

[0022] Figure 3 A distortion diagram of the optical lens provided for the embodiment one of the present application;

[0023] Figure 4 A structural schematic diagram of the optical lens provided for the embodiment two of the present application;

[0024] Figure 5 An MTF diagram of the optical lens provided for the embodiment two of the present application;

[0025] Figure 6 A distortion diagram of the optical lens provided for the embodiment two of the present application;

[0026] Figure 7 The structural schematic diagram of the optical lens provided for Embodiment Three of the present application is shown in the following figure:

[0027] Figure 8 The MTF diagram of the optical lens provided for Embodiment Three of the present application is shown in the following figure:

[0028] Figure 9 The distortion diagram of the optical lens provided for Embodiment Three of the present application is shown in the following figure.

[0029] In the figures, the various reference signs mean:

[0030] First cemented lens J1; second cemented lens J2; third cemented lens J3; fourth cemented lens J4;

[0031] First lens L1; second lens L2; third lens L3; fourth lens L4; fifth lens L5; sixth lens L6; seventh lens L7; eighth lens L8; ninth lens L9; eleventh lens L11; twelfth lens L12; cover glass L20; diaphragm STOP. DETAILED DESCRIPTION

[0032] For the convenience of understanding, the English abbreviations and related technical terms involved in the embodiments of the present application are explained and described below.

[0033] Focal power, equal to the difference between the convergence degree of the image-side beam and the convergence degree of the object-side beam, which represents the ability of the optical lens to deflect light rays.

[0034] The focal power of a lens or lens group is positive, the lens or lens group has a positive focal length, and has the effect of converging light rays.

[0035] The focal power of a lens or lens group is negative, the lens or lens group has a negative focal length, and has the effect of diverging light rays.

[0036] Focal length, also known as focal length, is a measure of the convergence or divergence of light in an optical lens, which refers to the vertical distance from the optical center of the lens or lens group to the focal plane when an infinite distant object forms a clear image through the lens or lens group. For a fixed focus lens, the position of the optical center is fixed; for a long focus lens, the change of the optical center of the lens leads to the change of the focal length of the lens.

[0037] Effective focal length (EFL) of the lens refers to the distance from the center of the lens to the focal point.

[0038] Synthetic focal length is the combination of the focal lengths of each lens in a lens group.

[0039] Object side, the side of the lens where the object is located.

[0040] Image side, the side of the lens where the image of the object is located.

[0041] Aperture diaphragm, a device used to control the amount of light passing through the lens and into the camera body, usually located within the lens.

[0042] Object plane, the surface on which the object is placed, located on the object side of all lenses in the optical lens.

[0043] Optical axis, an axis that passes through the center of the lens. The optical axis of the lens is the axis that passes through the center of each lens in the lens.

[0044] Focal point, the point where parallel light rays converge after being refracted by a lens or lens group.

[0045] Abbe number, the ratio of the difference in refractive index of an optical material at different wavelengths, representing the degree of dispersion of the material.

[0046] Aberration, the deviation of the actual intersection point of light rays passing through the lens from the ideal optical system on the optical axis. The point on the object where the near-axis light rays intersect the image plane is called the near-axis image point. However, the actual intersection point of light rays passing through the lens at different apertures is not exactly the same as the near-axis image point, and there is a certain deviation. These deviations are collectively referred to as aberration.

[0047] Distortion, also known as distortion, the degree of distortion of the image formed by the optical lens relative to the object itself. Distortion is caused by the influence of the aperture spherical aberration. The intersection height of the chief ray of different fields passing through the optical lens and the Gaussian image plane is not equal to the ideal image height, and the difference between the two is the distortion.

[0048] The technical solutions in the embodiments of the present application will be described in detail below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0049] In the embodiments of the present application, the terms "first", "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0050] As shown in Figure 1 , Figure 4 and Figure 7 , the embodiments of the present application provide a microscope comprising an optical lens.

[0051] The optical lens described above can be, but is not limited to, an objective lens of a microscope.

[0052] As shown in Figure 1 , the optical lens comprises twelve lenses; from the image side to the object side, the lens located at the first position (such as the first lens L1 in Figure 1 ) and the lens located at the second position (such as the second lens L2 in Figure 1 ) form a first cemented lens J1, and the power of the first cemented lens J1 is negative.

[0053] In the twelve lenses of the optical lens in the embodiments of the present application, from the image side to the object side, the lens located at the first position and the lens located at the second position form a first cemented lens, that is, the first position close to the image side is a first cemented lens, the power of the first cemented lens is negative, forming a reverse telephoto structure, which not only can well lengthen the working distance, but also can reduce the tolerance sensitivity of the optical lens, at the same time, by reasonably allocating the powers of the twelve lenses, the aberration of the optical lens is smaller, which is more conducive to the improvement of the resolution, in addition, the assembly of the optical lens is facilitated.

[0054] It should be noted that the optical lens described above is a semi-closed wireless optical conjugate system, which belongs to a wireless conjugate system. Parallel light rays are transmitted from the image side to the object side through the optical lens to the object plane, and the light rays close to the object plane converge on the object plane, that is, the light rays close to the image side are wireless, so it is called a semi-closed wireless optical conjugate system.

[0055] In the design process of the optical lens described above, the main optical parameters are important.

[0056] In the embodiments of the present application, the focal length EFL of the optical lens satisfies the relationship: 3.5≤EFL≤6.5.

[0057] By reasonably selecting the powers of the lenses, when the focal length of the optical lens satisfies the above relationship, it is conducive to reducing the aberration of the optical lens, thereby being conducive to improving the resolution of the optical lens.

[0058] The entrance pupil diameter ENTD of the optical lens satisfies the relationship: 6.6≤ENTD≤9.5.

[0059] When the entrance pupil diameter ENTD is smaller, the numerical aperture NA is smaller, and the working distance is larger.

[0060] By reasonably selecting the entrance pupil diameter of the optical lens, the numerical aperture can be appropriately reduced, so that the purposes of considering large numerical aperture and long working distance are achieved.

[0061] In addition, the F number and the relative aperture of the optical lens are also related to the focal length EFL and the entrance pupil diameter ENTD, so by reasonably selecting the two optical parameters of the focal length EFL and the entrance pupil diameter ENTD, the F number and the relative aperture of the optical lens can also be reasonably selected, so that the performance of the optical lens meets the requirements.

[0062] Therefore, in summary, the optical lens achieves the purposes of considering large numerical aperture, long working distance, and high resolution.

[0063] In some embodiments, the total optical length TTL of the optical lens satisfies the relationship: TTL≤68mm.

[0064] Through the above settings, the optical lens can be matched with different barrels to achieve different magnifications, and the length of the entire system can be adjusted according to actual needs in cooperation with the barrel.

[0065] In some embodiments, the radius of curvature R Figure 1 of the image side surface of the lens arranged at the last position from the image side to the object side (such as the twelfth lens L12 in 12A and the radius of curvature R 12B of the object side surface satisfy the relationship: 0.267≤R 12A / R 12B ≤0.514.

[0066] When the above comparison is small, the field curvature of the optical lens is corrected, but the aberration is not well corrected; when the above comparison is large, not only the process processing difficulty of the twelfth lens L12 is increased, and the coating is not good, but also the aberration of the optical lens is increased.

[0067] When the above relationship is satisfied, not only the process processing difficulty of the twelfth lens L12 is reduced, and the coating is facilitated, but also the aberration is reduced, thereby being beneficial to improve the resolution.

[0068] In some embodiments, the three lenses arranged at the last three positions from the image side to the object side (such as the twelfth lens L12, the thirteenth lens L13, and the fourteenth lens L14 in Figure 1the combination focal length F of the tenth lens L10, the eleventh lens L11 and the twelfth lens L12 10_11_12 satisfies the relationship: 1.26 ≤ F 10_11_12 / EFL ≤ 2.1.

[0069] the above F 10_11_12 is the combination focal length of the three lenses arranged in the last three positions from the image side to the object side in the optical lens, i.e., the sum of the focal lengths of the tenth lens L10, the eleventh lens L11 and the twelfth lens L12.

[0070] When the above F 10_11_12 is relatively small, i.e., the combination focal length F of the tenth lens L10, the eleventh lens L11 and the twelfth lens L12 10_11_12 is relatively small, it is difficult to achieve; when the above F 10_11_12 is relatively large, i.e., the combination focal length F of the tenth lens L10, the eleventh lens L11 and the twelfth lens L12 10_11_12 is relatively large, it will result in a relatively long length of the optical lens, which is not conducive to the miniaturization design of the optical lens.

[0071] When the above ratio satisfies the above relationship, the tenth lens L10, the eleventh lens L11 and the twelfth lens L12 are arranged in close succession in turn, so that the optical lens is conducive to reducing the length of the optical lens on the basis of meeting the optical requirements, thereby facilitating the miniaturization design of the optical lens.

[0072] It should be noted that close succession means that the gap between the two adjacent lenses is small.

[0073] In some embodiments, the maximum aperture D MAX and the minimum aperture D MIN satisfy the relationship: 1.809 < |D MAX / D MIN | < 2.5.

[0074] When |D MAX / D MIN | is too small, the aperture of the optical lens as a whole is relatively uniform, but the design difficulty of the optical lens is increased; when |D MAX / D MIN | is too large, the difference between the maximum aperture and the minimum aperture of the optical lens is relatively large, resulting in a relatively large volume of the optical lens as a whole.

[0075] When the maximum aperture D MAX and the minimum aperture D MINWhen the absolute value of the difference between the maximum and minimum of the diameter of the optical lens satisfies the above relationship, the optical lens satisfies the optical requirements, and the difference between the maximum and minimum of the diameter of the optical lens is reduced, that is, the diameter of the optical lens as a whole is relatively uniform. Therefore, when the optical lens is placed in the lens barrel, the space utilization in the lens barrel is relatively high, so that the purposes of miniaturization design of the optical lens and improving the space utilization of the lens barrel in which the optical lens is placed are achieved.

[0076] Figure 1 A structure diagram of the optical lens of embodiment one is shown. The optical lens comprises, in order from the image side to the object side, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a stop STOP, a tenth lens L10, an eleventh lens L11, a twelfth lens L12, and a cover glass L20; the first lens L1 and the second lens L2 form a first cemented lens J1, the third lens L3, the fourth lens L4, and the fifth lens L5 form a second cemented lens J2, and the sixth lens L6 and the seventh lens L7 form a third cemented lens J3; the optical power of the first cemented lens J1 is negative, the optical power of the second cemented lens J2 is negative, and the optical power of the third cemented lens J3 is positive.

[0077] The tenth lens L10, the eleventh lens L11, and the twelfth lens L12 in the embodiment of the present application are in close contact in order. The interval between the tenth lens L10, the eleventh lens L11, and the twelfth lens L12 is specifically referred to Table 1a.

[0078] Tables 1a to 1d respectively give the specific parameter values of each lens of the optical lens of an optional embodiment in the embodiment one of the present application.

[0079] Table 1a

[0080] Surface No. Surface Type R Value Thickness Refractive Index Abbe Number Sur 1 Standard 35.413 1.778 1.922859 20.8846 Sur 2 Standard -18.619 1 1.58599 64.5999 Sur 3 Standard 7.636 20.548 Sur 4 Standard 32.784 3.784 1.497 81.6128 Sur 5 Standard -10.985 1 2.00069 25.4258 Sur 6 Standard 17.027 4.081 1.5928 68.342 Sur 7 Standard -22.017 0.1 Sur 8 Standard 37.268 6.362 1.5928 68.342 Sur 9 Standard -11.096 1 1.497 81.6128 Sur 10 Standard -92.042 0.1 STOP Standard 17.265 5.562 1.5928 68.342 Sur 12 Standard -21.76 1 1.672707 32.181 Sur 13 Standard 14.115 2.778 Sur 14 Standard Infinity 0.1 Sur 15 Standard 37.413 2.47 1.922859 20.8846 Sur 16 Standard -65.41 0.1 Sur 17 Standard 12.854 2.583 1.755 52.3001 Sur 18 Standard 25.897 0.1 Sur 19 Standard 7.459 3.618 1.755 52.3001 Sur 20 Standard 17.455 1.136 Sur 21 Standard Infinity 0.7 1.501371 56.4092 Sur 22 Standard Infinity 0.1 1.4645 65.7687 Sur 23 Standard Infinity 3.05

[0081] It should be noted that in Table 1a, the “surface serial number” is the serial number of each surface arranged in order from the object side to the image side, the radius R value is the curvature radius of the object side surface or the image side surface of the lens corresponding to the surface number, that is, the curvature radius of the object side surface or the image side surface of the lens corresponding to each surface serial number at the optical axis, “Infinity” in the “curvature radius” parameter series of the lens means that the object side surface or the image side surface of the lens is a plane; the value of “Sur23” at the “thickness” is the working distance of the optical lens.

[0082] The optical parameters of the optical lens in embodiment one and the relationship satisfied are shown in Table 1b.

[0083] Table 1b

[0084] Parameter Numerical Aperture Object Field Angle CRA Angle Working Distance Value 0.8 0.25 0.8 3.05 mm Parameter EFL ENTD TTL Value 4.486 mm 8.589 mm 63.05 mm Relationship [R 12A / R 12B ]]> |D MAX / D MIN |]]> F 10_11_12 / EFL]]> Value 0.427 2.022 1.677

[0085] Note: The following notes explain the relationship of the optical lens in each of the embodiments:

[0086] EFL is the focal length of the optical lens;

[0087] ENTD is the entrance pupil diameter of the optical lens;

[0088] TTL is the total track length of the optical lens;

[0089] F 10_11_12 is the combined focal length of the three lenses arranged from the image side to the object side in the last three positions in the optical lens, i.e., the sum of the focal lengths of the tenth lens L10, the eleventh lens L11, and the twelfth lens L12;

[0090] R 12A is the radius of curvature of the image side surface of the lens arranged from the image side to the object side in the last position in the optical lens, i.e., the radius of curvature of the image side surface of the twelfth lens L12;

[0091] R 12B is the radius of curvature of the object side surface of the lens arranged from the image side to the object side in the last position in the optical lens; i.e., the radius of curvature of the object side surface of the twelfth lens L12;

[0092] CRA (Chief Ray Angle) is the Chinese name for "Chief Ray Angle". In optical lens design, CRA refers to the maximum angle of the light rays that can be focused onto the pixels on the sensor side of the optical lens, and the pixel responsivity at this angle is 80% of the zero-degree pixel responsivity.

[0093] The positive and negative cases of the refractive power of each lens in the optical lens in Embodiment One are shown in Table 1c.

[0094] Table 1c

[0095]

[0096] It should be noted that "+" and "-" in Table 1c represent the positive and negative cases of the refractive power of each lens in the optical lens in Embodiment One. "+" represents the refractive power of the lens being positive; "-" represents the refractive power of the lens being negative.

[0097] The concave-convex condition of the object side surface or the image side surface at the optical axis in each lens in the optical lens in Embodiment One is shown in Table 1d.

[0098] Table 1d

[0099]

[0100] It should be noted that in Table 1d, "-+", "+-", and "--" represent the concavity or convexity of the object-side or image-side of each lens at the optical axis. Specifically, "-+" indicates that the object-side of the lens is concave towards the object side at the optical axis, while the image-side is convex towards the object side; "+-" indicates that both the object-side and image-side of the lens are convex towards the object side at the optical axis, i.e., a biconvex structure; and "--" indicates that both the object-side and image-side of the lens are concave towards the object side at the optical axis. Of course, in addition to the concave and convex configurations mentioned above, the lenses in an optical lens can also include any one or more of the following: "++", "∞+", "+∞", "∞-", and "-∞". "++" represents that both the object-side and image-side surfaces of the lens are convex towards the object side at the optical axis; "∞+" represents that the object-side surface of the lens is flat at the optical axis, and the image-side surface is convex towards the object side at the optical axis; "+∞" represents that the object-side surface of the lens is convex towards the object side at the optical axis, and the image-side surface is flat at the optical axis; "∞-" represents that the object-side surface of the lens is flat at the optical axis, and the image-side surface is concave towards the object side at the optical axis; "-∞" represents that the object-side surface of the lens is concave towards the object side at the optical axis, and the image-side surface is flat at the optical axis. No specific limitations are made here.

[0101] Combination Figure 1 The schematic diagram of the optical lens in Embodiment 1 and the main parameters of the optical lens in Embodiment 1 given in Tables 1a, 1c and 1d show that the first lens in the optical lens of this embodiment is a biconvex lens with positive optical power, the second lens is a biconcave lens with negative optical power, the third lens is a biconvex lens with positive optical power, the fourth lens is a biconcave lens with negative optical power, the fifth lens is a biconvex lens with positive optical power, the sixth lens is a biconvex lens with positive optical power, the seventh lens is a meniscus lens with negative optical power, the eighth lens is a biconvex lens with positive optical power, the ninth lens is a biconcave lens with negative optical power, the tenth lens is a biconvex lens with positive optical power, the eleventh lens is a meniscus lens with positive optical power, and the twelfth lens is a meniscus lens with positive optical power.

[0102] In the optical lens of Embodiment 1, the optical power of the first lens L1, the third lens L3, and the fifth lens L5 is positive.

[0103] The refractive index of the first lens L1 is nd L1 The Abbe number is 1.922859 (vd). L1 It is 20.8846.

[0104] The refractive index of the third lens L3 is nd L3 The Abbe number vd is 1.497. L3 It is 81.6128.

[0105] The refractive index nd of the fifth lens L5 L5 The Abbe number vd is 1.5928.L5 It is 68.342.

[0106] Combination Figure 1 The schematic diagram of the optical lens in Example 1, and the relationships between the main parameters of the optical lens in Example 1 given in Tables 1a to 1d and Table 1b, as well as the concavity and convexity of each lens at the optical axis, are shown. The MTF and distortion diagrams of the optical lens in Example 1 are obtained through simulation, as follows: Figure 2 and Figure 3 As shown.

[0107] in: Figure 2 The image shown is an MTF chart of the optical lens provided in Embodiment 1 of this application. MTF is short for Modulation Transfer Function, which is a function that describes the modulation degree as a function of spatial frequency. The MTF chart is a graph reflecting the contrast (fidelity) reproduction of the optical lens. The horizontal axis of the MTF chart is the distance from the center to the edge, and the vertical axis reflects the quality of contrast, or in other words, the quality of fidelity.

[0108] Figure 3 This is a distortion diagram of the optical lens provided in Embodiment 1 of this application. The distortion diagram represents the percentage distortion of the optical lens as the field of view changes, where the horizontal axis represents the percentage distortion and the vertical axis represents the normalized field of view height.

[0109] The above descriptions of the MTF plot and distortion plot are the same as those in other embodiments, and will not be repeated below.

[0110] from Figure 2 It can be seen that the MTF of the 0-1.0 field-of-view lens is greater than 0.6 at 100lp / mm, 200lp / mm, 300lp / mm and 400lp / mm, indicating that the optical lens has good color reproduction, high resolution and excellent imaging.

[0111] from Figure 3 It can be seen that the distortion of the optical lens is less than 0.02%.

[0112] Figure 4 A structural diagram of the optical lens of Embodiment 2 is shown. The main difference between the optical lens of Embodiment 2 and the optical lens of the first embodiment described above lies in the structure of the seventh lens, as well as the different parameters and conditions satisfied by each lens.

[0113] Tables 2a to 2d provide the specific parameter values ​​for each lens of the optical lens in one of the optional embodiments of Embodiment 2 of this application.

[0114] Table 2a

[0115] Surface No. Surface Type R Value Thickness Refractive Index Abbe Number Sur 1 Standard 75.522 2.605 1.94595 17.942 Sur 2 Standard -20.906 2.776 1.497 81.6128 Sur 3 Standard 7.358 24.832 Sur 4 Standard 31.451 2.998 1.5928 68.342 Sur 5 Standard -12.62 1 1.92286 20.8799 Sur 6 Standard 16.588 3.289 1.437001 95.1004 Sur 7 Standard -19.233 0.1 Sur 8 Standard 14.023 4.015 1.617998 63.4058 Sur 9 Standard -24.097 1.113 1.497 81.6128 Sur 10 Standard 28.381 1.524 STOP Standard 12.313 3.944 1.570989 50.7999 Sur 12 Standard -18.002 1.015 1.699678 34.9255 Sur 13 Standard 8.651 2.13 Sur 14 Standard Infinity 0.1 Sur 15 Standard 27.289 1.868 1.92286 20.8799 Sur 16 Standard -54.33 0.1 Sur 17 Standard 9.386 1.704 1.92286 20.8799 Sur 18 Standard 13.015 0.1 Sur 19 Standard 6.325 3.388 1.755 52.3221 Sur 20 Standard 19.943 0.598 Sur 21 Standard Infinity 0.7 1.501371 56.4092 Sur 22 Standard Infinity 0.1 1.4645 65.7687 Sur 23 Standard Infinity 2.8

[0116] The optical parameters of the optical lens in Example 2 and the relationships they satisfy are shown in Table 2b.

[0117] Table 2b

[0118]

[0119] The optical power of each lens in the optical lens of Example 2 is shown in Table 2c.

[0120] Table 2c

[0121]

[0122] The concavity or convexity of the object side or image side of each lens in the optical lens of Embodiment 2 at the optical axis is shown in Table 2d.

[0123] Table 2d

[0124]

[0125] Combination Figure 4 From the schematic diagram of the optical lens in Example 2 and the main parameters of the optical lens in Example 1 given in Tables 2a, 2c, and 2d, it can be seen that the seventh lens in this example is a biconcave lens with negative optical power. In this example, the number of lenses is the same as in Example 1. Except for the structure and optical power of the seventh lens L7, which differ from those in Example 1, the other aspects, including the optical power and concavity / convexity of the lenses, are the same as in Example 1 and will not be repeated here.

[0126] In the optical lens of Embodiment 2, the optical power of the first lens L1, the third lens L3, and the fifth lens L5 is positive.

[0127] The refractive index of the first lens L1 is nd L1 The Abbe number vd is 1.94595. L1 It is 17.942.

[0128] The refractive index of the third lens L3 is nd L3 The Abbe number vd is 1.5928. L3 It is 68.342.

[0129] The refractive index nd of the fifth lens L5 L5 The Abbe number vd is 1.437001. L5 The value is 95.1004.

[0130] Combination Figure 4The structure diagram of the optical lens in Example Two and the main parameters of the optical lens in Example Two given in Table 2a to Table 2d satisfy the relationship of Table 2b, and the concave-convex condition of each lens at the optical axis. The MTF diagram and the distortion diagram of the optical lens in Example Two obtained by simulation are shown in Figure 5 and Figure 6 .

[0131] From Figure 5 it can be seen that the MTF of the 0-1.0 field lens at 100 lp / mm, 200 lp / mm, 300 lp / mm and 400 lp / mm are all greater than 0.5, which indicates that the optical lens has good resolution and high resolution, and the imaging is excellent.

[0132] From Figure 6 it can be seen that the distortion of the optical lens is less than 0.08%.

[0133] Figure 7 The structure diagram of the optical lens in Example Three is shown. In this embodiment, the number of lenses and the frame in the optical lens are the same as those in Example One, and the main difference between the optical lens in Example Three and the optical lens in the first embodiment is that the parameters of each lens and the conditions satisfied are different.

[0134] Table 3a to Table 3d respectively give the specific parameter values of each lens of an optical lens in an optional embodiment of Example Three of the present application.

[0135] Table 3a

[0136] Surface No. Surface Type R Value Thickness Refractive Index Abbe Number Sur 1 Standard 44.772 1.692 1.92286 20.8799 Sur 2 Standard -22.315 1 1.437001 95.1004 Sur 3 Standard 7.475 27.727 Sur 4 Standard 51.775 2.597 1.60625 63.711 Sur 5 Standard -10.468 1 1.92286 20.8799 Sur 6 Standard 15.448 2.727 1.525005 70.3302 Sur 7 Standard -21.292 4 Sur 8 Standard 17.947 4.57 1.613091 60.3837 Sur 9 Standard -10.997 1 1.497003 81.1382 Sur 10 Standard 43.125 0.1 STOP Standard 19.769 3.864 1.58286 59.5046 Sur 12 Standard -10.607 2.981 1.728277 28.5326 Sur 13 Standard 13.05 1.647 Sur 14 Standard Infinity 0.375 Sur15 Standard 60.905 1.897 1.92286 20.8799 Sur16 Standard -25.363 0.487 Sur17 Standard 10.791 1.704 1.92286 20.8799 Sur18 Standard 17.801 0.1 Sur19 Standard 5.859 3.022 1.72903 54.0413 Sur20 Standard 14.966 0.709 Sur21 Standard Infinity 0.7 1.501371 56.4092 Sur22 Standard Infinity 0.1 1.4645 65.7687 Sur23 Standard Infinity 2.68

[0137] The optical parameters of the optical lens in Example Three and the relationship satisfied are shown in Table 3b.

[0138] Table 3b

[0139] Parameter Numerical Aperture Object Field Angle CRA Angle Working Distance Value 0.69 0.27 0.5 2.68mm Parameter EFL ENTD TTL Value 4.79mm 8.81mm 66.679mm Relationship [R 12A / R 12B ]]> |D MAX / D MIN |]]> F 10_11_12 / EFL]]> Value 0.391 1.556 1.222

[0140] The optical power of each lens in the optical lens in Example Three is shown in Table 3c.

[0141] Table 3c

[0142]

[0143] The concave-convex condition of the object side or the image side of each lens in the optical lens in Example Three at the optical axis is shown in Table 3d.

[0144] Table 3d

[0145]

[0146] In the optical lens of Embodiment 3, the optical power of the first lens L1, the third lens L3, and the fifth lens L5 is positive.

[0147] The refractive index of the first lens L1 is nd L1 The Abbe number is 1.92286 (vd). L1 It is 20.8799.

[0148] The refractive index of the third lens L3 is nd L3 The Abbe number vd is 1.60625. L3 The value is 63.711.

[0149] The refractive index nd of the fifth lens L5 L5 The Abbe number vd is 1.525005. L5 It is 70.3302.

[0150] Combination Figure 7 The schematic diagram of the optical lens in Example 3, and the main parameters of the optical lens in Example 3 as shown in Tables 3a to 3d, which satisfy the relationship in Table 3b, as well as the concavity and convexity of each lens at the optical axis. The MTF and distortion diagrams of the optical lens in Example 3 were obtained through simulation, as shown below. Figure 8 and Figure 9 As shown.

[0151] from Figure 8 It can be seen that the MTF of the 0-1.0 field-of-view lens is greater than 0.65 at 100lp / mm, 200lp / mm, 300lp / mm and 400lp / mm, indicating that the optical lens has good color reproduction, high resolution and excellent imaging.

[0152] from Figure 9 It can be seen that the distortion of the optical lens is less than 0.05%.

[0153] In summary, when the optical lens of this application is used as a microscope objective, its numerical aperture can reach 0.8, its maximum working distance can reach 4.4 mm, and its maximum object-side field of view can reach 0.3. Combined with the MTF and distortion diagrams in the three embodiments above, it is evident that this optical lens achieves a balance between large numerical aperture, long working distance, and high resolution. That is, this microscope can also achieve a balance between large numerical aperture, long working distance, and high resolution.

[0154] Embodiment 4 of this application also provides a camera module, which includes an optical lens and a photosensitive element (not shown in the figure), with the photosensitive element located on the image side of the optical lens.

[0155] The working principle of the camera module is that light reflected by a photographed object forms an optical image through an optical lens and projects onto a photosensitive surface of a photosensitive element, and the photosensitive element converts the optical image into an electric signal, i.e., an analog image signal, and transmits the electric signal to a processor.

[0156] The photosensitive element (also referred to as an image sensor) is a kind of semiconductor chip, and the surface thereof contains hundreds of thousands to millions of photodiodes. When the surface is irradiated by light, electric charges are generated. The photosensitive element can be a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS). The CCD is made of a kind of high-sensitivity semiconductor material and can convert light into electric charges. The charge coupled device is composed of a plurality of light-sensitive units, usually in units of millions of pixels. When the surface of the photosensitive element is irradiated by light, each light-sensitive unit reflects electric charges on the component, and the signals generated by all the light-sensitive units are added together to form a complete picture.

[0157] The camera module mainly uses the refraction principle of the lens to form an image, i.e., object light passes through the optical lens to form a clear image on the focal plane, and the image of the object is recorded by the photosensitive element located on the focal plane.

[0158] In this embodiment, the structure of the optical lens is the same as that of the optical lens in Embodiments 1 to 3, and the effects achieved are the same, which will not be described here again.

[0159] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An optical lens applied to a microscope, characterized in that, The optical lens comprises twelve lenses; In the direction from the image side to the object side, the lens located at the first position and the lens located at the second position form a first cemented lens, the first cemented lens has a negative optical power; The focal length EFL of the optical lens satisfies the relationship: 3.5≤EFL≤6.5; The entrance pupil diameter ENTD of the optical lens satisfies the relationship: 6.6≤ENTD≤9.

5.

2. The optical lens according to claim 1, wherein The total track length TTL of the optical lens satisfies the relationship: TTL≤68mm.

3. The optical lens according to claim 1, wherein Curvature radius R of the image side surface of the lens arranged in the last position from the image side to the object side 12A and the curvature radius R of the object side surface 12B satisfies the relationship: 0.267 ≤ R 12A / R 12B ≤ 0.

514.

4. The optical lens according to claim 1, wherein Combined focal length F of the group of three lenses arranged last in the order from image side to object side 10_11_12 The focal length EFL of the optical lens satisfies the relationship: 1.26 ≤ F 10_11_12 / EFL ≤ 2.

1.

5. The optical lens according to claim 1, wherein The maximum aperture D of the optical lens MAX The absolute value of the minimum aperture D MIN satisfies the relationship: 1.809 < |D MAX / D MIN | < 2.

5.

6. The optical lens according to any one of claims 1-5, wherein The optical lens comprises, in order from the image side to the object side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, and a twelfth lens; the first lens and the second lens form the first cemented lens, the third lens, the fourth lens, and the fifth lens form a second cemented lens, and the sixth lens and the seventh lens form a third cemented lens.

7. The optical lens according to any one of claims 1-5, wherein The optical lens comprises, in order from the image side to the object side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, and a twelfth lens; the first lens is a biconvex lens with a positive optical power, the second lens is a biconcave lens with a negative optical power, the third lens is a biconvex lens with a positive optical power, the fourth lens is a biconcave lens with a negative optical power, the fifth lens is a biconvex lens with a positive optical power, the sixth lens is a biconvex lens with a positive optical power, the seventh lens is a meniscus lens or a biconcave lens with a negative optical power, the eighth lens is a biconvex lens with a positive optical power, the ninth lens is a biconcave lens with a negative optical power, the tenth lens is a biconvex lens with a positive optical power, the eleventh lens is a meniscus lens with a positive optical power, and the twelfth lens is a meniscus lens with a positive optical power.

8. The optical lens according to claim 6, wherein The second cemented lens has a negative optical power, and the third cemented lens has a positive optical power.

9. The optical lens according to claim 6, wherein The optical lens further comprises a diaphragm, and the diaphragm is located between the ninth lens and the tenth lens.

10. The optical lens according to claim 6, wherein The optical lens further comprises a cover glass, and the cover glass is located on the side of the twelfth lens close to the object plane.

11. A microscope, characterized by Comprising: The optical lens according to any one of claims 1-10.

12. A camera module, comprising: Comprising: The optical lens according to any one of claims 1-10; A photosensitive element is disposed on an image side of the optical lens.

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